#include <stdio.h>
int fun(char *s)
{
int i=0;
while(s[i] != '\0')
{
if(!(s[i] >= '0' && s[i] <= '9'))
{
printf("%c\n",s[i]);
return -1;
}
i++;
}
return 0;
}
int main(void)
{
char a[50];
printf("please input num:\n");
scanf("%s",a);
if(!fun(a))
{
printf("go on\n");
}
else
{
printf("end\n");
return -1;
}
return 0;
}